Measurement reporting method of terminal and terminal using same

ABSTRACT

Provided are a measurement reporting method of a terminal in which a primary cell is set and a terminal apparatus using the measurement reporting method. The method comprises: a step for adding a secondary cell; a step for determining whether the secondary cell is applicable to related measurement; and a step for determining whether the secondary cell is included in a cellsTriggeredList, wherein when the secondary cell is not applicable to the related measurement and the secondary cell is included in the cellsTriggeredList, the secondary cell is removed from the cellsTriggeredList.

CROSS REFERENCE TO RELATED APPLICATIONS:

This application is the National Phase of PCT International ApplicationNo. PCT/KR2014/008749, filed on Sep. 19, 2014, which claims priorityunder 35 U.S.C. 119(e) to U.S. Provisional Application No. 61/880,795,filed on Sep. 20, 2013, all of which are hereby expressly incorporatedby reference into the present application.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a method for performing a measurementreport of a terminal in a mobile communication system and a terminal forthe same.

Related Art

The International Telecommunication Union Radio communication sector(ITU-R) performs a standardization work of International MobileTelecommunication (IMT)-Advanced which is a next-generation mobilecommunication system after 3^(rd) generation.

3rd Generation Partnership Project (3GPP) as a system standard thatmeets requirements of the IMT-Advanced prepares for LTE-Advanced(hereinafter, referred to as LTE-A) acquired by enhancing long termevolution (LTE) based on Orthogonal Frequency Division Multiple Access(OFDMA)/Single Carrier-Frequency Division Multiple Access (SC-FDMA). TheLTE-A is one of dominant candidates for the IMT-Advanced.

Candidate technologies to be used in the LTE-A include carrieraggregation (CA). The carrier aggregation is a technology thataggregates a plurality of component carriers (CCs) having a narrow bandto configure a wideband. The component carriers include a downlinkcomponent carrier and an uplink component carrier. A cell may be definedas a pair of the downlink component carrier and the uplink componentcarrier or the downlink component carrier and in this case, the carrieraggregation may be appreciated as aggregation of a plurality of cells.

In the carrier aggregation, a primary cell in which a terminalestablishes an initial connection process/reconnection process with abase station and a secondary cell added in addition to the primary cellare provided.

Meanwhile, in a mobile communication system, supporting mobility of theterminal is required. To this end, the terminal continuously measures aquality for a serving cell providing a current service and a quality fora neighboring cell. The terminal reports a measurement result to anetwork at an appropriate time and the network provides optimal mobilityto the terminal through handover, and the like.

The terminal may report the measurement result by a method triggered byan event. That is, when a specific event occurs, the terminal reportsthe measurement result. In this case, a target cell of each event ispredetermined. For example, among events, events are for the servingcell, the neighboring cell, the primary cell, and the secondary cell,respectively or events are for combinations of the cells are provided.The secondary cell is basically treated as the serving cell, but may betreated as the neighboring cell in the specific event.

When the neighboring cell satisfies the specific event, the terminalmakes the neighboring cell be included in ‘cellsTriggeredList’. Acurrent standard prescribes that the neighboring cell is included in‘measResultNeighCells’ to be transmitted if the ‘cellsTriggeredList’ isnot empty and the neighboring cell is not included in the‘measResultNeighCells’ but excluded if the ‘cellsTriggeredList’ isempty.

The base station may add the neighboring cell to the terminal as thesecondary cell by using a measurement report including the‘measResultNeighCells’. In this case, the neighboring cell needs to bebasically treated as a serving cell.

However, the current standard does not prescribe modification of the‘cellsTriggeredList’ when the neighboring cell is added as the secondarycell. Therefore, the neighboring cell continuously remains in the‘cellsTriggeredList’, and as a result, the neighboring cell is includedin the ‘measResultNeighCells’ to be transmitted.

This causes unnecessary measurement report transmission of the terminalto bring about battery consumption. Further, when the base stationperforms resource management based on the ‘measResultNeighCells’,ambiguity may occur.

SUMMARY OF THE INVENTION

The present invention provides a method for performing a measurementreport and an apparatus for the same when a secondary cell is added to aterminal that supports carrier aggregation.

In one aspect, provided is a method for a measurement reporting of auser equipment (UE) configured a primary cell. The method includesadding a secondary cell, determining whether the secondary cell isapplicable for an associated measurement and determining whether thesecondary cell is included in a triggered cell list(cellsTriggeredList). If the secondary cell is not applicable for theassociated measurement and if the secondary cell is included in thetriggered cell list, the UE removes the secondary cell from thetriggered cell list.

If the secondary cell satisfies a specific event, the UE may include thesecondary cell in the triggered cell list.

The specific event may be an event that channel state of a neighbor cellis better than a threshold.

The triggered cell list may be transmitted through a radio resourcecontrol (RRC) message.

The triggered cell list may comprise a physical cell identity of a cell.

The primary cell may be a cell in which the UE performs an initialconnection establishment procedure or a connection re-establishmentprocedure.

The secondary cell may be a cell which is used for providing additionalradio resources in addition to the primary cell.

In another aspect, provided is a user equipment (UE) configured aprimary cell. The UE includes a radio frequency (RF) unit fortransmitting and receiving a radio signal and a processor coupled to theRF unit. The processor is configured to add a secondary cell, determinewhether the secondary cell is applicable for an associated measurementand determine whether the secondary cell is included in a triggered celllist (cellsTriggeredList). If the secondary cell is not applicable forthe associated measurement and if the secondary cell is included in thetriggered cell list, the UE removes the secondary cell from thetriggered cell list.

Since unnecessary measurement report transmission of a terminal can bereduced, power consumption of the terminal can be reduced. Further,ambiguity can be reduced in terms of resource management between a basestation and the terminal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a network structure of an evolved universal terrestrialradio access network (E-UTRAN) as an example of a mobile communicationsystem.

FIG. 2 and FIG. 3 show a structure of a radio interface protocol betweena UE and an E-UTRAN on the basis of a 3GPP radio access networkprotocol.

FIG. 4 is a picture for describing radio link failure procedure.

FIG. 5 and FIG. 6 show success and failure cases of an RRC connectionre-establishment procedure.

FIG. 7 shows a procedure in which a UE performs a measurement to reportto a network in a 3GPP LTE system.

FIG. 8 shows an example of a measurement configuration configured in aUE.

FIG. 9 shows an example of deleting a measurement identity.

FIG. 10 shows an example of deleting a measurement object.

FIG. 11 is a drawing for describing the aforementioned measurementoperation in summary.

FIG. 12 is a drawing for describing a carrier aggregation techniqueapplied to a 3GPP LTE-A system.

FIG. 13 is a drawing for describing a definition on a cell from aperspective of a UE when a carrier aggregation technique is applied.

FIG. 14 illustrates a case in which the secondary cell is included inthe ‘measResultNeighCells’.

FIG. 15 is an operating method of the terminal supporting carrieraggregation.

FIG. 16 describes S1601 to S1603 of FIG. 15.

FIG. 17 is a diagram illustrating a configuration of an embodiment of awireless communication system including a terminal apparatus and a basestation apparatus according to the present invention.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

As one example of a wireless communication system, a 3Gpp LTE/LTE-Abased system is assumed, but various wireless communication systems maybe variously applied, to which a carrier aggregation technology, such asan IEEE 802.16 based system, or the like may be applied. Throughout thespecification, like reference numerals refer to like elements.

In the following description, ‘measurement’ may be prescribed asreceiving reference signals received from cells positioned atinter-frequency, intra-frequency, and inter-radio access technology(RAT) according to measurement configuration which a terminal receivesfrom a network to measure a quality value of a corresponding cell.Further, in the following description, the ‘measurement’ means a signalquality or a cell quality determined through the reference signalreceived from the measurement target cell.

As one example of a wireless communication/mobile communication systemfor applying the present invention, a 3GPP LTE system will be describedin brief.

FIG. 1 shows a network structure of an evolved universal terrestrialradio access network (E-UTRAN) as an example of a mobile communicationsystem. An E-UTRAN system is evolved from the legacy UTRAN system, andits basic standardization work is carried out in the current 3GPP. TheE-UTRAN system is also referred to as a long term evolution (LTE)system.

The E-UTRAN consists of e-NodeBs (eNBs or base stations). The eNBs areconnected with each other through an X2 interface. The eNB is connectedto a user equipment (hereinafter, UE) through a radio interface, and isconnected to an evolved packet core (EPC) through an S1 interface.

EPC comprises MME (Mobility Management Entity), S-GW (Serving-Gateway)and PDN-GW (Packet Data Network-Gateway). The MME has access informationof the UE or information regarding capacity of the UE, and theinformation is frequently used in mobility management of the UE. TheS-GW is a gateway having the E-UTRAN as an end point, and the P-GW is agateway having the PDN as an end point.

Layers of a radio interface protocol between the UE and the network maybe divided into a first layer L1, a second layer L2, and a third layerL3 based on three lower layers of an open system interconnection (OSI)standard model which is widely known in the communication system, andamong them, a physical layer to which the first layer belongs providesan information transfer service using a physical channel, and a radioresource control (RRC) layer positioned on the third layer serves tocontrol a radio resource between the UE and the network. To this end,the RRC layer exchanges an RRC message between the UE and the network.

FIG. 2 and FIG. 3 show a structure of a radio interface protocol betweena UE and an E-UTRAN on the basis of a 3GPP radio access networkprotocol.

The radio interface protocol horizontally includes a physical layer, adata link layer, and a network layer, and vertically includes a userplane (U-plane) for data information transfer and a control plane(C-plane) for control signaling delivery. Protocol layers of FIG. 2 andFIG. 3 can be classified into a first layer (L1), a second layer (L2),and a third layer (L3) on the basis of lower three layers of an opensystem interconnection (OSI) model that is well-known in thecommunication system. A pair of radio protocol layers exits between theUE and the UTRAN and serves to transmit data of a radio link.

Hereinafter, each of the radio protocol layers of the control plane ofFIG. 2 and the user plane of FIG. 3 will be described.

A physical layer, i.e., a first layer, provides an upper layer with aninformation transfer service by using a physical channel. The physicallayer is connected to a media access control (MAC) layer, i.e., an upperlayer of the physical layer, via a transport channel. Data istransferred between the MAC layer and the physical layer through thetransport channel. The data move between different PHY layers, that is,the PHY layers of the transmitter and the receiver through the physicalchannel. The physical channel may be modulated by an orthogonalfrequency division multiplexing (OFDM) scheme, and use a time and afrequency as the radio resource.

The medium access control (hereinafter, MAC) layer in a second layerprovides services to a radio link control (RLC) layer, i.e., an upperlayer of the MAC layer, through a logical channel. A radio link control(hereinafter, RLC) layer in the second layer supports reliable datatransfer. Functions of the RLC layer may be implemented as a functionblock included in the MAC layer. In this case, the RLC layer may notexist. A packet data convergence protocol (PDCP) layer in the secondlayer performs a header compression function for decreasing an Internetprotocol (IP) header size containing relatively large and unnecessarycontrol information in order to effectively transmit the IP packetthrough a radio interface when transmitting an IP packet such as an IPv4packet or an IPv6 packet.

A radio resource control (hereinafter, RRC) layer in a third layer isdefined only in the control plane. The RRC layer serves to control thelogical channel, the transport channel, and the physical channel inassociation with configuration, reconfiguration, and release of radiobearers (RBs). In this case, the RB is a service provided by the secondlayer for data delivery between the UE and the E-UTRAN. When RRCconnection is established between the RRC layer of the UE and the RRClayer of the E-UTRAN, the UE is in an RRC connected state, and if not,the UE is in an RRC idle state.

A downlink transport channel for transporting the data to the UE fromthe network includes a broadcast channel (BCH) for transporting systeminformation and a downlink shared channel (SCH) for transporting usertraffic or a control message. The traffic or the control message of adownlink multicast or broadcast service may be transported through thedownlink SCH, or may be transported through a separate downlinkmulticast channel (MCH). Meanwhile, an uplink transport channel fortransporting the data from the UE to the network includes a randomaccess channel (RACH) for transporting an initial control message and anuplink shared channel (SCH) for transporting the user traffic or thecontrol message in addition to the RACH.

A logical channel which is above the transport channel and mapped in thetransport channel includes a broadcast control channel (BCCH), a pagingcontrol channel (PCCH), a common control channel (CCCH), a multicastcontrol channel (MCCH), a multicast traffic channel (MTCH), and thelike.

The physical channel is constituted by several OFDM symbols in a timedomain and several sub-carriers in a frequency domain. One sub-frame isconstituted by a plurality of OFDM symbols in the time domain. The RB asa resource allocation unit is constituted by a plurality of OFDM symbolsand a plurality of sub-carriers. Further, each sub-frame may usespecific sub-carriers of specific OFDM symbols (for example, first OFDMsymbols) of the corresponding sub-frame for the physical downlinkcontrol channel (PDCCH), that is, a L1/L2 control channel. One subframemay consist of two slots having a length of 0.5 ms, which may correspondto 1 ms equivalent to a transmission time interval (TTI) as a unit timein which data is transmitted.

Next, system information in an LTE system will be described. The systeminformation includes necessary information which must be known to a UEto access an eNB. Thus, the UE has to receive all pieces of systeminformation before accessing the eNB. Further, the UE must always haverecent system information. Since the system information is informationwhich must be known to all UEs in one cell, the eNB periodicallytransmits the system information.

The system information is classified into a master information block(MIB), a scheduled block (SB), and a system information block (SIB). TheMIB allows the UE to know a physical configuration (e.g., bandwidth) ofa specific cell. The SB reports transmission information (e.g., atransmission period or the like) of SIBs. The SIB is a group of aplurality of pieces of system information related to each other. Forexample, one SIB includes only information of a neighbor cell, andanother SIB includes only information of an uplink radio channel used bythe UE.

Meanwhile, a service provided by the network to the UE may be classifiedinto three types to be described below. The UE recognizes a cell typedifferently according to which service can be provided. A service typeis first described below, and then the cell type will be described.

1) Limited service: This service provides an emergency call and anearthquake and tsunami warning system (ETWS), and can be provided in anacceptable cell.

2) Normal service: This service denotes a public use service for generaluse, and can be provided in a suitable cell.

3) Operator service: This service denotes a service for a networkoperator, and a corresponding cell can be used only by the networkoperator and cannot be used by a normal user.

A service type provided by a cell can be identified as follows.

1) Acceptable cell: A UE can receive a limited service in this cell.This cell is not barred from the perspective of the UE, and satisfies acell selection criterion of the UE.

2) Suitable cell: The UE can receive a normal service in this cell. Thiscell satisfies a condition of an acceptable cell, and also satisfiesadditional conditions. Regarding the additional conditions, this cellmust belong to a PLMN to which the UE can access, and a tracking areaupdate procedure of the UE must not be barred in this cell. If aspecific cell is a CSG cell, this cell must be accessible by the UE as aCSG member.

3) Barred cell: This is a cell which uses system information tobroadcast that the cell is a barred cell.

4) Reserved cell: This is a cell which uses system information tobroadcast that the cell is a reserved cell.

Hereinafter, an RRC state of the UE and an RRC connection method will bedescribed. The RRC state means whether the RRC layer of the UE islogical-connected with the RRC layer of the E-UTRAN or not, and a casewhere the RRC layer of the UE is connected with the RRC layer of theE-UTRAN is called a RRC connection state, and a case where the RRC layerof the UE is not connected with the RRC layer of the E-UTRAN is calledan RRC idle state. Since the RRC connection exists in the UE in the RRCconnection state, the E-UTRAN may determine the existence of thecorresponding UE in a cell unit, and as a result, the UE may beefficiently controlled. On the other hand, the UE in the RRC idle statemay not be determined by the E-UTRAN, and a core network (CN) is managedby a tracking area unit which is a larger area unit than the cell. Thatis, in the UE in the RRC idle state, only the existence is determined bya large area unit, and the UE needs to move in the RRC connection statein order to receive a general mobile communication service such as voiceor data

When the user first turns on the power of the UE, the UE first searchesa proper cell and then stays in the RRC idle state in the correspondingcell. The UE in the RRC idle state establishes the RRC connection withthe E-UTRAN through an RRC connection procedure only when the RRCconnection is required, and is transited into the RRC connection state.There are several cases where the UE in the RRC idle state requires theRRC connection, and for example, uplink data transmission is requireddue to reasons such as user's call attempt, or a response message to acase where a paging message is received from the E-UTRAN is transmitted.

A non-access stratum (NAS) layer positioned above the RRC layer performsfunctions such as a session management and a mobility management.

In the NAS layer, in order to manage mobility of the UE, two states ofEDEPS mobility management-REGISTERED (EMM-REGISTER) and EMM-DEREGISTEREDare defined, and the two states are applied to the UE and the MME. Theinitial UE is in the EMM-DEREGISTERED state, and the UE performs aprocedure of registering the UE in the corresponding network through aninitial attaching procedure so as to be connected to the network. Whenthe attaching procedure is successfully performed, the UE and the MMEare in the EMM-REGISTERED state.

In order to manage signaling connection between the UE and the EPC, twostates of an EPS connection management (ECM)-IDLE state and anECM-CONNECTED state, and the two states are applied to the UE and theMME. When the UE in the ECM-IDLE state is RRC-connected with theE-UTRAN, the corresponding UE becomes in the ECM-CONNECTED state. Whenthe MME in the ECM-IDLE state is S1-connected with the E-UTRAN, thecorresponding MME becomes in the ECM-CONNECTED state. When the UE is inthe ECM-IDLE state, the E-UTRAN does not have context information of theUE. Accordingly, the UE in the ECM-IDLE state performs a procedurerelated with the mobility based on the UE such as cell selection or cellreselection without receiving a command of the network. On the contrary,when the UE is in the ECM-CONNECTED state, the mobility of the UE ismanaged by the command of the network. When a position of the UE in theECM-IDLE state is different from a position which is known to thenetwork, the UE notifies the corresponding position of the UE to thenetwork through a tracking area updating procedure.

FIG. 4 shows a radio link failure procedure in a 3GPP LTE system.

A UE persistently performs a measurement to maintain a communicationlink quality with a cell in which the UE receives a service. Inparticular, the UE determines whether the communication link qualitywith the cell in which the UE currently receives and provides theservice is in a communication disabled situation. If it is determinedthat the quality of the current cell is so poor that communication isimpossible at present, the UE declares a radio link failure. If the UEdeclares the radio link failure, the UE gives up maintaining ofcommunication with this cell, selects a cell through a cell selectionprocedure, and thereafter attempts an RRC connection reconfiguration. Assuch, an operation related to the radio link failure may be described intwo phases as shown in FIG. 4.

In a first phase, the UE examines whether a current communication linkhas a problem. If there is the problem, the UE declares a radio linkproblem, and waits until this communication link is recovered during aspecific time T₁. If the link is recovered during this time, the UEcontinues a normal operation. If the radio link problem is not recoveredduring the time T₁ in the first phase, the UE declares the radio linkfailure, and enters a second phase. In the second phase, the UE performsan RRC connection re-establishment procedure to recover from the radiolink failure.

The RRC connection re-establishment procedure is a procedure ofreconfiguring an RRC connection again in an RRC_CONNECTED state. Sincethe UE remains in the RRC_CONNECTED state, that is, does not enter anRRC_IDLE state, the UE does not initiate all radio configurations (e.g.,radio bear configurations) thereof. Instead, the UE temporarily suspendsthe use of all radio bearers except for an SRB0 when starting the RRCconnection re-establishment procedure. If the RRC connectionreconfiguration is successful, the UE resumes the use of the radiobearers of which the use is temporarily suspended.

FIG. 5 and FIG. 6 show success and failure cases of an RRC connectionre-establishment procedure.

Referring to FIG. 5 and FIG. 6, an operation of a UE in an RRCconnection re-establishment procedure will be described. First, the UEperforms a cell selection to select one cell. In the selected cell, theUE receives system information to receive basic parameters for a cellaccess. Subsequently, the UE attempts an RRC connection re-establishmentthrough a random access procedure. If a cell selected by the UE throughthe cell selection is a cell having a context of the UE, that is, aprepared cell, the cell may accept an RRC connection re-establishmentrequest of the UE, and thus the RRC connection re-establishmentprocedure may be successful. However, if the cell selected by the UE isnot the prepared cell, since the cell does not have the context of theUE, the RRC connection re-establishment request of the UE cannot beaccepted. Therefore, the RRC connection re-establishment procedurefails.

Hereinafter, a quality measurement procedure in a 3GPP LTE system willbe described.

FIG. 7 shows a procedure in which a UE performs a measurement to reportto a network in a 3GPP LTE system.

First, the UE may receive measurement configuration information from aBS (S710). Hereinafter, a message including the measurementconfiguration information is called a measurement configuration message.The UE may perform a measurement on the basis of the measurementconfiguration information (S720). If a measurement result satisfies areport condition in the measurement configuration information, the UEmay report a measurement result to the BS (S730). Hereinafter, a messageincluding the measurement result is called a measurement report message.

Meanwhile, the measurement configuration message received from the BSmay have the following structure.

TABLE 1 RRCConnectionReconfiguration-r8-IEs ::= SEQUENCE { measConfigMeasConfig OPTIONAL, -- Need ON } MeasConfig ::= SEQUENCE { --Measurement objects measObjectToRemoveList MeasObjectToRemoveListmeasObjectToAddModList MeasObjectToAddModList -- Reportingconfigurations reportConfigToRemoveList ReportConfigToRemoveListreportConfigToAddModList ReportConfigToAddModList -- Measurementidentities measIdToRemoveList MeasIdToRemoveList measIdToAddModListMeasIdToAddModList -- Other parameters quantityConfig QuantityConfigmeasGapConfig MeasGapConfig OPTIONAL, -- Need ON s-Measure RSRP-RangeOPTIONAL, -- Need ON preRegistrationInfoHRPD PreRegistrationInfoHRPDspeedStatePars CHOICE { release NULL, setup SEQUENCE {mobilityStateParameters MobilityStateParameters, timeToTrigger-SFSpeedStateScaleFactors } } OPTIONAL, -- Need ON ... }

The measurement configuration information in the measurementconfiguration message exemplified in Table 1 above will be described asfollows.

(1) Measurement object information: The measurement object informationis information on an object for which the UE is to perform ameasurement. A measurement object may include at least one of anintra-frequency measurement object which is an object of an intra-cellmeasurement, an inter-frequency measurement object which is an object ofan inter-cell measurement, and an inter-RAT measurement object which isan object of an inter-RAT measurement. For example, the intra-frequencymeasurement object may indicate the neighbor cell having the samefrequency band as the serving cell, the inter-frequency measurementobject may indicate the neighbor cell having the different frequencyband from the serving cell, and the inter-RAT measurement object mayindicate a neighbor cell of RAT different from the RAT of the servingcell.

(2) Reporting configuration information: The reporting configurationinformation is information on a reporting condition and a reporting typeregarding the time when the UE reports the measurement result. Thereporting condition may include information on an event or a cycle inwhich reporting the measurement result is triggered. The reporting typeis information regarding a configuration type of the measurement result.

(3) Measurement identity information: The measurement identityinformation is information regarding a measurement identity thatdetermines a measurement object, a reporting time, and a reporting typeby the UE by associating the measurement object and the reportingconfiguration with each other. The measurement identity information isincluded in the measurement reporting message to represent a measurementobject of the measurement result and a reporting condition of themeasurement reporting which occurs.

(4) Quantity configuration information: The quantity configurationinformation is information on a parameter for configuring filtering of ameasurement unit, a reporting unit, and/or a measurement result value.

(5) Measurement gap information: The measurement gap information isinformation on a measurement gap which is an interval which the UE mayuse for only measurement without considering data transportation withthe serving cell because downlink transportation or uplinktransportation is not scheduled.

The UE may have a measurement object list, a measurement reportingconfiguration list, and a measurement identity list in order to performa measurement procedure.

In the 3GPP LTE, the base station may configure only one measurementobject for one frequency band to the UE. According to Clause 5.5.4 of3GPP TS 36.331 V8.5.0 (2009-03) “Evolved Universal Terrestrial RadioAccess (E-UTRA) Radio Resource Control (RRC); Protocol specification(Release 8)”, events that trigger the measurement reporting shown in thefollowing table are defined.

TABLE 2 Event Report condition Event A1 Serving becomes better thanthreshold Event A2 Serving becomes worse than threshold Event A3Neighbor becomes offset better than serving Event A4 Neighbor becomesbetter than threshold Event A5 Serving becomes worse than threshold1 andneighbor becomes better than threshold2 Event B1 Inter RAT neighborbecomes better than threshold Event B2 Serving becomes worse thanthreshold1 and inter RAT neighbor becomes better than threshold2

Referring to Table 2 given above, for example, event A1 is an event inwhich a serving cell has a better channel state than a threshold, eventA2 is an event in which the serving cell has a worse channel state thanthe threshold, and event A3 is an event in which a neighboring cell hasthe better channel state than the serving cell by an offset value. Asanother example, it may be known that event A4 is an event in which theneighboring cell shows the better channel state than the threshold.Event A5 is an event in which the serving cell has a worse channel statethan threshold 1 and the neighboring cell has a better channel statethan threshold 2.

When a measurement result of the terminal (UE) satisfies the event(quality measurement report criterion), the terminal transmits ameasurement report message to the base station.

FIG. 8 shows an example of a measurement configuration configured in aUE.

In the example of FIG. 8, First, measurement identity 1 connects theintra-frequency measurement object and reporting configuration 1. The UEperforms intra frequency measurement and the reporting configuration 1is used to determine a reference and a reporting type of reporting themeasurement result.

Measurement identity 2 is connected with the intra-frequency measurementobject similarly to the measurement identity 1, but the intra-frequencymeasurement object is reporting configuration 2. The UE performsmeasurement and the reporting configuration 2 is used to determine thereference and the reporting type of reporting the measurement result.

By the measurement identity 1 and the measurement identity 2, the UEtransports the measurement result even though the measurement result forthe intra-frequency measurement object satisfies any one of thereporting configuration 1 and the reporting configuration 2.

Measurement identity 3 connects inter-frequency measurement object 1 andreporting configuration 3. When a measurement result for theinter-frequency measurement object 1 satisfies a reporting conditionincluded in the reporting configuration 1, the UE reports themeasurement result.

Measurement identity 4 connects the inter-frequency measurement object 2and the reporting configuration 2. When a measurement result for theinter-frequency measurement object 2 satisfies a reporting conditionincluded in the reporting configuration 2, the UE reports themeasurement result.

Measurement identity connects measurement target and reportconfiguration. Each report configuration may comprise an eventtriggering a measurement report. Therefore, it can be expressedmeasurement identity connects the measurement target and the specificevent. Here, it can be expressed that the measurement for evaluatingwhether the specific event is satisfied and the measurement target areassociated (Or it can be expressed, for a convenience, that the specificevent is the measurement associated with the measurement target).

Meanwhile, the measurement object, the reporting configuration, and/orthe measurement identity may be added, changed, and/or deleted. Thesemay be instructed when the base station sends a new measurementconfiguration message or a measurement configuration change message tothe UE.

FIG. 9 shows an example of deleting a measurement identity.

In FIG. 9, a “NW command” may be a measurement configuration message ora measurement configuration change message which instructs to delete ameasurement identity 2. If the measurement identity 2 is deleted,measurement for a measurement object associated with the measurementidentity 2 902 is stopped and a measurement report is not transported. Ameasurement object or a reporting configuration associated with thedeleted measurement identity may not be changed.

FIG. 10 shows an example of deleting a measurement object.

In FIG. 10, a “NW command” may be a measurement configuration message ora measurement configuration message which instructs to delete aninter-frequency measurement object 1. If the inter-frequency measurementobject 1 is deleted, a UE may also delete a related measurement identity3. Accordingly, a measurement for the inter-frequency measurement object1 is suspended, and a measurement report may not be transmitted.However, a report configuration related to the deleted inter-frequencymeasurement object 1 may not be changed or deleted.

When the reporting configuration is removed, the UE removes even ameasurement identity associated therewith. The UE stops measurement foran associated measurement object by the associated measurement identity.However, the measurement object associated with the deleted reportingconfiguration may not be changed or deleted.

FIG. 11 is a drawing for describing the aforementioned measurementoperation in summary.

A UE may receive measurement configuration information from an eNB (or anetwork) (S1101). As described above with reference to Table 1 above,the measurement configuration information may include measurement objectinformation, reporting configuration information, measurement identityinformation, quantity configuration information, and measurement gapinformation. In addition, as described above with reference to FIG. 9and FIG. 10, the measurement configuration information may includeinformation such as a specific measurement object and/or a specificmeasurement identity deletion/addition or the like.

Table 3 shows one example of a conventional report configurationmessage.

TABLE 3 -- ASN1START ReportConfigEUTRA ::= SEQUENCE { triggerType CHOICE{ event SEQUENCE { eventId CHOICE { eventA1 SEQUENCE { a1-ThresholdThresholdEUTRA }, eventA2 SEQUENCE { a2-Threshold ThresholdEUTRA },eventA3 SEQUENCE { a3-Offset INTEGER (−30..30), reportOnLeave BOOLEAN },eventA4 SEQUENCE { a4-Threshold ThresholdEUTRA }, eventA5 SEQUENCE {a5-Threshold1 ThresholdEUTRA, a5-Threshold2 ThresholdEUTRA }, ...,eventA6-r10 SEQUENCE { a6-offset-r10 INTEGER (−30..30),a6-ReportOnLeave-r10 BOOLEAN } }, hysteresis Hysteresis, timeToTriggerTimeToTrigger }, periodical SEQUENCE { purpose ENUMERATED {reportStrongestCells, reportCGI} } }, triggerQuantity ENUMERATED {rsrp,rsrq}, reportQuantity ENUMERATED {sameAsTriggerQuantity, both},maxReportCells INTEGER (1..maxCellReport), reportIntervalReportInterval, reportAmount ENUMERATED{r1, r2, r4, r8, r16, r32, r64,infinity}, ..., [[ si-RequestForHO-r9 ENUMERATED {setup} OPTIONAL, --Cond reportCGI ue-RxTxTimeDiffPeriodical-r9 ENUMERATED {setup} OPTIONAL-- Need OR ]], [[ includeLocationInfo-r10 ENUMERATED {true} OPTIONAL, --Need OR reportAddNeighMeas-r10 ENUMERATED {setup} OPTIONAL -- Need OR ]]} ThresholdEUTRA ::= CHOICE{ threshold-RSRP RSRP-Range, threshold-RSRQRSRQ-Range } -- ASN1STOP

In Table 3, ‘a3-Offset/a6-Offset’ represents an offset value in ameasurement report triggering condition for event A3/A6.

‘aN-ThresholdM’ represents a threshold used in a measurement reporttriggering condition for event aN.

‘eventId’ represents selection of E-UTRA for an event triggering reportrequirement.

‘maxReportCells’ represents the maximum number (excluding the servingcell) of cells included in the measurement report.

‘reportAmount’ represents the number of measurement reports which may beapplied to triggerType in addition to triggerType periodical.

reportOnLeave/a6-reportOnLeave indicates whether a measurement reportprocess needs to start when satisfying a leaving condition with respectto one cell in cellsTriggeredList.

reportQuantity represents a quantity to be included in the measurementreport.

timeToTrigger represents a time when an event needs to satisfy aspecific condition in order to trigger the measurement report.

triggerQuatity represents a quantity used for evaluating the conditionto trigger the event.

The UE may perform a quality measurement according to the receivedmeasurement configuration information (S1102). Accordingly, the UE mayperform a measurement result evaluation procedure for determiningwhether a quality measurement result value satisfies a quality reportcriterion (S1103). In this case, an evaluation criterion may use methodsshown in Table 2 above. If the measurement result satisfies the reportcriterion (S1104), the UE may construct measurement report informationincluding the measurement result (S1105), and may transmit theinformation to the eNB (i.e., the network) (S1106). An exemplarystructure of the measurement report message that can be used when it isapplied to the 3GPP LTE system is as follows.

TABLE 4 MeasResults ::= SEQUENCE { measId MeasId, measResultServCellSEQUENCE { rsrpResult RSRP-Range, rsrqResult RSRQ-Range },measResultNeighCells CHOICE { measResultListEUTRA SEQUENCE (SIZE(1..maxCellReport)) OF physCellId PhysCellId, measResult SEQUENCE {rsrpResult RSRP-Range OPTIONAL, rsrqResult RSRQ-Range OPTIONAL, ..., } }

Information included in the measurement report message exemplified inTable 4 above may be as follows.

measurement identity (measId): It is a measurement identity related tothe report configuration of which the report criterion is satisfied. Thenetwork may know which criterion is used to transmit the measurementreport received from the UE through this measurement identity.

measured serving cell's quality value (measResultServCell): It is aquality value of a serving cell measured by the UE. For example, it mayinclude a reference signal received power (RSRP) and a reference signalreceived quality (RSRQ).

measured neighbour cell's information (measResultNeighCells): It is ameasurement identity of a neighbour cell measured by the UE, andincludes the followings.

neighbour cell identity (physCellId): In general, it is a physical cellidentity (e.g., PCI for E-UTRAN) of a neighbour cell satisfying a reportcriterion.

neighbour cell's quality value (measResult): In general, it is a qualityvalue (e.g., RSRP, RSRQ) of a neighbour cell satisfying a reportcriterion.

The measurement report message may be transmitted in the form of ahigher layer signal, for example, an RRC message.

According to the aforementioned example, the terminal efficientlyperforms a quality measurement of the serving cell and/or neighboringcell and reports the quality measurement to the base station toguarantee mobility of the terminal. However, in the present invention,when the secondary cell is additionally added to the terminal withrespect to such a measurement operation, an efficient measurement reportoperation is intended to be proposed. To this end, first, as one exampleof a case in which the terminal has a plurality of serving cells, acarrier aggregation (CA) technology discussed in a 3GPP LTE-A standardwill be described.

FIG. 12 is a diagram for describing a carrier aggregation technologyapplied to a 3GPP LTE-A system.

An LTE-A technology standard as an IMT-Advanced candidate technology ofthe International Telecommunication Union (ITU) is designed to meetIMT-Advanced technological requirements of the ITU. As a result, inLTE-A, a discussion about extending a bandwidth as compared with theconventional LTE system is in progress in order to satisfy therequirements of the ITU. In the LTE-A system, in order to extend thebandwidth, a carrier which may be provided in the conventional LTEsystem is defined as a component carrier (hereinafter, referred to asCC) and it is discussed that a maximum of 5 CCs may be bound and used.Since the CC may have a maximum of 20 MHZ bandwidth like the LTE system,the CC is a concept to extend the bandwidth up to at least 100 MHz. Atechnology that binds and uses a plurality of CCs is called carrieraggregation (CA).

FIG. 13 is a diagram for describing a definition of a cell from thepoint of view of a terminal when a carrier aggregation technology isapplied.

As described above in association with FIG. 12, when the CA is applied,each of a downlink (DL) and an uplink (UL) may include a plurality ofCCs. In such a system, from the viewpoint of the terminal, each of acombination (cell 0 of FIG. 13) of the DL CC and the UL CC or only theDL CC (cell 1 of FIG. 13) may be regarded as the cell. As illustrated inFIG. 13, a connection relationship between the DL CC and the UL CC maybe indicated through system information transmitted through a DLresource. That is, system information of the mobile communication systemto which the CA is applied additionally includes information on theconnection relationship between the UL CC and the UL CC and isillustrated as an SIB2 linkage in FIG. 13.

Meanwhile, in the LTE-A system, proposed is a concept in which CCs towhich all control signaling is transmitted are distinguished from otherCCs are referred to as primary CCs. A UL primary CC and a DL primary CCare constituted per each terminal and a combination of a UL primary CCused for UL control information transmission and a DL primary CC usedfor DL control information transmission may be referred to as a primarycell or PCell. Except for the primary cell or PCell, cells constitutedin the terminal may be referred to as a secondary cell or SCell.

Alternatively, the primary cell is a cell that operates in a primaryfrequency and may be defined as a cell in which the terminal starts aninitial connection establishment procedure or a connectionre-establishment procedure. Alternatively, the primary cell may bedefined as a cell indicated as the primary cell during a handoverprocess.

The secondary cell is a cell that operates in a secondary frequency andmay be defined as a cell used for providing an additional radio resourceexcept for the primary cell. After RRC connection establishment, thesecondary cell may be configured.

Now, the present invention will be described.

According to a current standard regulation, the terminal operates asfollows in association with the measurement report triggered by theevent.

1. Triggering Phase.

1) The terminal determines which cell is applicable to a predeterminedevent. For example, only the serving cell may be applied to events A1and A2 and only the neighboring cell may be applied to event A4. Thatis, the serving cell is an applicable cell with respect to events A1 andA2 and the neighboring cell is the applicable cell with respect to eventA4.

However, the secondary cell is exceptionally regarded as the neighboringcell with respect to events A3 and A5. In another case, the secondarycell is regarded as the serving cell. That is, an exceptional rule forthe secondary cell is applied to events A3 and A5.

2) The terminal evaluates whether to satisfy a concerned event withrespect to the applicable cell(s).

3) If the applicable cell satisfies the concerned event, the cell isincluded in a cell list (‘cellsTriggeredList’, hereinafter, the same asabove). The triggered cell list may be a list including cells thatsatisfy a specific event. The triggered cell list may be a listincluding cells that satisfy each event among applicable cells to eachevent. The triggered cell list may be configured for each event or for aplurality of events. The triggered cell list may include a physical cellidentity (ID) of the cell.

2. Reporting Phase.

4) The terminal constitutes ‘measResultPcell’ and‘measResultServFreqList’. Only when an applicable neighboring cell whichneeds to be reported is present, the terminal constitutes‘measResultNeighCells’. Among events of the ‘cellsTriggeredList’, anapplicable neighboring cell which needs to be reported with respect tothe concerned event may be included in the ‘measResultNeighCells’.

A table given below shows a detailed example of the measurement reportmessage which the terminal reports.

TABLE 5 -- ASN1START MeasResults ::= SEQUENCE { measId MeasId,measResultPCell SEQUENCE { rsrpResult RSRP-Range, rsrqResult RSRQ-Range}, measResultNeighCells CHOICE { measResultListEUTRAMeasResultListEUTRA, measResultListUTRA MeasResultListUTRA,measResultListGERAN MeasResultListGERAN, measResultsCDMA2000MeasResultsCDMA2000, ... MeasResultServFreqList-r10 ::= SEQUENCE (SIZE(1..maxServCell- r10)) OF MeasResultServFreq-r10 MeasResultServFreq-r10::= SEQUENCE { servFreqId-r10 ServCellIndex-r10, measResultSCell-r10SEQUENCE { rsrpResultSCell-r10 RSRP-Range, rsrqResultSCell-r10RSRQ-Range } OPTIONAL, measResultBestNeighCell-r10 SEQUENCE {physCellId-r10 PhysCellId, rsrpResultNCell-r10 RSRP-Range,rsrqResultNCell-r10 RSRQ-Range } OPTIONAL, ... }

Meanwhile, when the terminal operates according to the current standardregulation, the terminal may operate as follows in association with thesecondary cell.

1. Events A1 and A2

1) The terminal regards the secondary cell as the serving cell.

2) That is, the secondary cell regarded as the serving cell is regardedto be applicable in evaluating events A1 and A2.

3) If the secondary cell satisfies events A1 and A2, the terminal makesthe secondary cell be included in the ‘cellsTriggeredList’.

4) However, since the secondary cell is regarded as the serving cell,there is no applicable neighboring cell which needs to be reported inthe ‘cellsTriggeredList’, and as a result, the terminal does notconstitute the ‘measResultNeighCells’. That is, the‘measResultNeighCells’ is not included in the measurement report. Theterminal transmits the measurement report including only the‘measResultPCel’ and the ‘measResultServFreqList’.

2. Event A3.

1) The terminal regards the secondary cell as the neighboring cell.

2) That is, the secondary is regarded to be applicable in evaluatingevent A3.

3) If the secondary cell satisfies event A3, the terminal makes thesecondary cell be included in the ‘cellsTriggeredList’.

4) The ‘cellsTriggeredList’ including the secondary cell is included inthe ‘measResultNeighCells’ of the measurement report. The terminaltransmits the measurement report including the ‘measResultPCel’, the‘measResultServFreqList’, and the ‘measResultNeighCells’.

3. Event A4.

1) The terminal regards the secondary cell as the serving cell.

2) That is, the secondary is regarded to be applicable in evaluatingevent A4.

3) Therefore, the secondary cell does not trigger the measurement reportby satisfaction of event A4.

4) There is no measurement report triggered by the secondary cell.

4. Event A5.

1) The terminal regards the secondary cell as the neighboring cell.

2) The secondary is regarded to be applicable in evaluating event A5.

3) If the secondary cell satisfies event A5, the terminal makes thesecondary cell be included in the ‘cellsTriggeredList’.

4) The ‘cellsTriggeredList’ including the secondary cell is included inthe ‘measResultNeighCells’ of the measurement report. The terminaltransmits the measurement report including the ‘measResultPCel’, the‘measResultServFreqList’, and the ‘measResultNeighCells’.

5. Event A6.

1) The terminal regards the secondary cell as the serving cell.

2) The secondary is regarded to be applicable in evaluating event A6.

3) Therefore, the secondary cell does not trigger event A6 and thesecond cell may not be included in the ‘cellsTriggeredList’. As aresult, the second cell may not be included in the‘measResultNeighCells’.

4) There is no measurement report triggered by the secondary cell.

As described, in the current standard, the measurement report followswhether to trigger (satisfy) the event and whether the secondary cell isincluded in the ‘measResultNeighCells’ varies depending on whether thesecondary cell being regarded as the serving cell or the neighboringcell. Therefore, when the network is implemented in such a manner torefer to contents of the ‘measResultNeighCells’ for radio resourcemanagement (RRM), the ambiguity may occur.

FIG. 14 illustrates a case in which the secondary cell is included inthe ‘measResultNeighCells’.

Referring to FIG. 14, cell 1 of an f1 frequency band may be configuredas the primary cell for the terminal. In addition, it is assumed thatcells 2, 3, and 4 in an f3 frequency band are configured as measurementtarget neighboring cells by a measurement configuration message. Thatis, it is assumed that cells 2, 3, and 4 are applicable cells withrespect to event A4.

When event A4 is satisfied with respect to cell 2, the terminal makescell 2 be included in the ‘cellsTriggeredList’. Then, since the‘cellsTriggeredList’ is not empty and cell 2 as the neighboring cell ispresent, the cells included in the ‘cellsTriggeredList’ are transmittedwhile being included in the ‘measResultNeighCells’.

Meanwhile, the terminal transmits the ‘measResultNeighCells’ andthereafter, cell 2 may be added as the secondary cell for the terminal.According to the conventional standard, when cell 2 as the neighboringcell is added as the secondary cell, how to modify the‘cellsTriggeredList’ is not prescribed. Further, according to theconventional standard, when the ‘cellsTriggeredList’ is not empty, thecells included in the ‘cellsTriggeredList’ are transmitted while beingincluded in the ‘measResultNeighCells’. Although cell 2 is added as thesecondary cell, and as a result, cell 2 is not the neighboring cell anylonger, cell 2 is included in the, therefore, there is a problem in thatthe terminal makes cell 2 be included in the ‘measResultNeighCells’ andtransmits cell 2 included in the ‘measResultNeighCells’ again. Thiscauses unnecessary power waste of the terminal and the ambiguity inradio resource management of the base station.

Hereinafter, application examples capable of the problem will bedescribed. The following examples may be applied to the conventionaloperations of the terminal, which include “1. Events A1 and A2” to “5.Event A6” described above through addition/modification.

The terminal may follow the aforementioned conventional operations whileonly one cell, for example, the primary cell is configured and operateas described in Application Example 1 or 2 given below when thesecondary cell is added. That is, while only the primary cell isconfigured for the terminal that supports the carrier aggregation, whenother cells except for the primary cell are added as the secondary cellof the terminal, Application Example 1 or 2 may be applied as below.

[Application Example 1]

The terminal may regard the secondary cell as the serving cell withrespect to a specific event. In this case, the secondary cell may beregarded as an unapplicable cell in evaluating the specific event.

For example, while only the primary cell is configured, cell 2 as theneighboring cell satisfies the specific event, and as a result, theterminal may transmit the measurement report. In this case, the terminalmay follow the conventional operations.

When cell 2 is added as the secondary cell, the terminal then regardscell 2 as the serving cell with respect to the specific event andregards cell 2 to be unapplicable in evaluating the event. If theapplicable cell of the specific event is the neighboring cell, cell 2 isnow regarded as the unapplicable cell with respect to the specificevent.

The terminal determines whether cell 2 added as the secondary cell isapplicable to related measurement. In the above example, since cell 2added as the secondary cell is not applicable to the specific event, theterminal removes cell 2 as the secondary cell from the‘cellsTriggeredList’.

When entries are not empty in the ‘cellsTriggeredList’ removed with thesecondary cell, the ‘cellsTriggeredList’ removed with the secondary cellis included in the ‘measResultNeighCells’. When the entries of the‘cellsTriggeredList’ removed with the secondary cell is empty, theterminal does not make the ‘measResultNeighCells’ be included in themeasurement report message. When the entries of the ‘cellsTriggeredList’removed with the secondary cell is empty, that is, the‘cellsTriggeredList’ is empty, the terminal may stop subsequentmeasurement report transmission associated with the related measurement.

The terminal transmits the measurement report message including the‘measResultPCel’, the ‘measResultServFreqList’, and the‘measResultNeighCells’.

[Application Example 2]

The terminal may regard the secondary cell as the neighboring cell withrespect to a specific event. The secondary cell may be regarded to beapplicable cell in evaluating the specific event.

When the secondary cell triggers the specific event, the terminal makesthe secondary cell be included in the ‘cellsTriggeredList’.

When the ‘cellsTriggeredList’ is included in the ‘measResultNeighCells’of the measurement report message, the terminal excludes the secondarycell. The terminal transmits the measurement report including the‘measResultPCel’, the ‘measResultServFreqList’, and the‘measResultNeighCells’ (when not empty). In this case, a different fromApplication Example 1 is that the secondary cell is regarded as theneighboring cell in evaluating the specific event, but the secondarycell may be regarded as the serving cell in constituting a field to beincluded in the measurement report message. Therefore, the secondarycell may be excluded from the field constituting the measurement reportmessage.

Application Example 1 will be described in more detail with reference toFIGS. 15 and 16.

FIG. 15 is an operating method of the terminal supporting carrieraggregation.

Referring to FIG. 15, the terminal performs a measurement report to thebase station (S1500). In the measurement report, when cell 2 as aneighboring cell satisfies event A4, cell 2 is included in‘cellsTriggeredList’, and as a result, it is assumed that cell 2 isincluded in ‘measResultNeighCells’. That is, it is assumed that the stepis performed, in which cell 2 is included in the cell list triggeredthrough satisfaction of a specific event.

The base station transmits configuration information ‘sCellToAddModList’on the secondary cell to be added in the terminal with reference to themeasurement report (S1501).

The terminal adds the secondary cell (S1502). The terminal may add thespecific cell as the secondary cell based on the configurationinformation on the secondary cell. For example, it is assumed that cell2 is added as the secondary cell. In this case, cell 2 as the secondarycell is regarded as a serving cell and the secondary cell is notapplicable to the related measurement event A4.

For example, when cell 2 as the neighboring cell and event A4 areindicated by a measurement identity, event A4 becomes the relatedmeasurement with respect to cell 2. As described above, the reason isthat the cell which is applicable to event A4 is the neighboring cell.However, when cell 2 is added to the terminal as the secondary cell tobe the serving cell, cell 2 is not applicable to event 4 at all.

The terminal performs S1601 to S1603 described in FIG. 16.

FIG. 16 describes S1601 to S1603 of FIG. 15.

Referring to FIG. 16, the terminal determines whether the secondary cellis applicable to the related measurement (S1601). In the example of FIG.15, on the assumption that cell 2 is added to the secondary cell, ifcell 2 is the neighboring cell and is related with event A4, the cell 2is applicable to the related measurement. Meanwhile, if cell 2 is theserving cell and is related with event A4, the cell 2 is not applicableto the related measurement. According to Application Example 1, sincecell 2 added as the secondary cell is regarded as the serving cellrelated with event A4, cell 2 is not applicable to the relatedmeasurement.

When the secondary cell is not applicable to the related measurement,the terminal determines whether the secondary cell is included in‘cellsTriggeredList’ (S1602).

When the secondary cell is included in the ‘cellsTriggeredList’, theterminal removes the secondary cell from the ‘cellsTriggeredList’(S1603).

That is, according to the present invention, the terminal excludes thesecondary cell which is not applicable to the related measurement fromthe measurement report. To this end, the secondary cell which is notapplicable to the related measurement is removed from the‘cellsTriggeredList’.

In the examples of FIGS. 15 and 16, in the state where only the primarycell is configured, according to the conventional terminal operation,cell 2 is regarded as the neighboring cell in evaluating specific event(e.g., A4) and included in the measurement report (S1500) to betransmitted to the base station. However, after cell 2 is added as thesecondary cell, i) according to Application Example 1, cell 2 isregarded as the serving cell in evaluating the specific event, or ii)cell 2 is referred to as the serving cell when constituting a field tobe included in a measurement report message according to ApplicationExample 2.

As a result, cell 2 is removed from the field ‘cellsTriggeredList’ to beincluded in the measurement report message defined with respect to thespecific event A4.

In Application Examples 1 and 2, the secondary cell was removed from the‘cellTriggeredList’ under a specific condition. Accordingly, thesecondary cell is excluded from the ‘measResultNeighCells’. Hereinafter,Application Examples in which the secondary cell is necessarily includedin the ‘measResultNeighCells’ will be described.

[Application Example 3]

The terminal may regard the secondary cell as the serving cell inevaluating a specific event and the secondary cell as the neighboringcell in constituting the field to be included in the measurement report.

That is, the secondary cell may be regarded to be applicable inevaluating specific events A1 and A2. When the secondary cell triggersthe specific event, the terminal makes the secondary cell be included inthe ‘cellsTriggeredList’.

The ‘cellsTriggeredList’ including the secondary cell is included in the‘measResultNeighCells’ of the measurement report. The terminal transmitsthe measurement report including the ‘measResultPCell’, the‘measResultServFreqList’, and the ‘measResultNeighCells’.

[Application Example 4]

The terminal regards the secondary cell as the serving cell with respectto a specific event. That is, the secondary cell may be regarded to beapplicable in evaluating specific events A1 and A2. When the secondarycell triggers the specific event, the terminal makes the secondary cellbe included in the ‘cellsTriggeredList’. In this case, the secondarycell is included in the ‘cellsTriggeredList’ as the neighboring cell aswell as the serving cell.

In respect to the specific event, the ‘cellsTriggeredList’ including thesecondary cell as the neighboring as well as the serving cell isincluded in the ‘measResultNeighCells’ of the measurement report. Inrespect to other events except for the specific event, only neighboringcells of the ‘cellsTriggeredList’ are included in the‘measResultNeighCells’. The terminal transmits the measurement reportincluding the ‘measResultPCell’, the ‘measResultServFreqList’, and the‘measResultNeighCells’.

FIG. 17 is a diagram illustrating a configuration of an embodiment of awireless communication system including a terminal apparatus and a basestation apparatus according to the present invention.

Referring to FIG. 17, each terminal (UE) apparatus may include areception module 1111, a transmission module 1112, a processor 1113, anda memory 1114. The reception module 1111 may receive various signals,data, information, and the like from a base station, and the like. Thetransmission module 1112 may receive various signals, data, information,and the like to the base station, and the like. Further, the receptionmodule 1111 may receive the measurement configuration informationincluding the reference information described above. The processor 1113adds a secondary cell and determines whether the secondary cell isapplicable to related measurement. In addition, in determining whetherthe secondary cell is included in ‘cellsTriggeredList’, when thesecondary cell is not applicable to the related measurement and thesecondary cell is included in the ‘cellsTriggeredList’, the secondarycell is removed from the ‘cellsTriggeredList’.

Meanwhile, the base station (eNB) apparatus may include a receptionmodule 1131, a transmission module 1132, a processor 1133, and a memory1134. The reception module 1131 may receive various signals, data,information, and the like from a terminal, and the like. Thetransmission module 1132 may receive various signals, data, information,and the like to the terminal, and the like.

The processor 1133 may transmit configuration information for thesecondary cell through the transmission module 1132 and receive ameasurement report message from the terminal through the receptionmodule 1131. The processor 1133 may manage mobility of the concernedterminal through the measurement report message received from theterminal. Besides, the processor 1133 performs a function to operateinformation received by the terminal apparatus, information to betransmitted to the outside, and the like and the memory 1134 may storethe operated information, and the like for a predetermined time and besubstituted with a component such as a buffer (not illustrated), or thelike.

The aforementioned embodiments and modifications can be implementedthrough various means. For example, the embodiments of the presentinvention can be implemented in hardware, firmware, software,combination of them, etc.

In case of the hardware implementation, the method according to theembodiments of the present invention can be implemented by one or moreapplication specific integrated circuits (ASICs), digital signalprocessors (DSPs), digital signal processing devices (DSPDs),programmable logic devices (PLDs), field programmable gate arrays(FPGAs), a processor, a controller, a microcontroller, a microprocessor,or the like.

What is claimed is:
 1. A method of measurement reporting of a userequipment (UE) which is configured with a primary cell, the methodperformed by the UE and comprising: adding a secondary cell as a servingcell of the UE; determining whether the secondary cell is applicable foran associated measurement among a plurality of measurements based onwhether the secondary cell is a serving cell or a neighboring cell,wherein the plurality of measurements comprises (i) a measurementapplicable to the serving cell and (ii) a measurement applicable to theneighboring cell; determining whether the secondary cell is alreadyincluded in a triggered cell list; and transmitting, to a base station,a measurement report including the triggered cell list, wherein based onthe secondary cell not being applicable for the associated measurementand based on the secondary cell already included in the triggered celllist, the secondary cell is removed by the UE from the triggered celllist, and wherein based on the secondary cell being applicable for theassociated measurement and satisfying a specific event, and based on thesecondary cell not included in the triggered cell list, the secondarycell is included by the UE in the triggered cell list.
 2. The method ofclaim 1, wherein the specific event is an event in which a channel stateof the neighboring cell is better than a threshold.
 3. The method ofclaim 1, wherein the triggered cell list comprises a physical cellidentity of a cell.
 4. The method of claim 1, wherein the primary cellis a cell in which the UE performs an initial connection establishmentprocedure or a connection re-establishment procedure.
 5. The method ofclaim 4, wherein the secondary cell is a cell which is used forproviding additional radio resources in addition to the primary cell. 6.A user equipment (UE) configured with a primary cell, the UE comprising:a radio frequency (RF) transceiver; at least one processor; and at leastone computer memory operably connectable to the at least one processorand storing instructions that, when executed by the at least oneprocessor, perform operations comprising: adding a secondary cell as aserving cell of the UE, determining whether the secondary cell isapplicable for an associated measurement among a plurality ofmeasurements based on whether the secondary cell is a serving cell or aneighboring cell, wherein the plurality of measurements comprises (i) ameasurement applicable to the serving cell and (ii) a measurementapplicable to the neighboring cell, determining whether the secondarycell is already included in a triggered cell list, and transmitting,through the RF transceiver to a base station, a measurement reportincluding the triggered cell list to a base station, wherein based onthe secondary cell not being applicable for the associated measurementand based on the secondary cell already included in the triggered celllist, the secondary cell is removed by the UE from the triggered celllist, and wherein based on the secondary cell being applicable for theassociated measurement and satisfying a specific event, and based on thesecondary cell not included in the triggered cell list, the secondarycell is included by the UE in the triggered cell list.
 7. The UE ofclaim 6, wherein the specific event is an event in which a channel stateof the neighboring cell is better than a threshold.
 8. The UE of claim6, wherein the triggered cell list comprises a physical cell identity ofa cell.
 9. The UE of claim 6, wherein the primary cell is a cell inwhich the UE performs an initial connection establishment procedure or aconnection re-establishment procedure.
 10. The UE of claim 9, whereinthe secondary cell is a cell which is used for providing additionalradio resources in addition to the primary cell.
 11. The method of claim1, wherein the associated measurement for which the secondary cell isapplicable is not included in the transmitted measurement report due tothe secondary cell having been removed from the triggered cell list. 12.The UE of claim 6, wherein the associated measurement for which thesecondary cell is applicable is not included in the transmittedmeasurement report due to the secondary cell having been removed fromthe triggered cell list.
 13. The method of claim 1, wherein theassociated measurement for which the secondary cell is applicable is nottransmitted in the measurement report to the base station due to thesecondary cell having been removed from the triggered cell list.
 14. TheUE of claim 6, wherein the associated measurement for which thesecondary cell is applicable is not transmitted in the measurementreport to the base station due to the secondary cell having been removedfrom the triggered cell list.